[FIX] b_easy_my_coop: Info Session must not be required field

In the form to become a new cooperator, the field info_session_confirmed
was required but not in the form validation. This commit fixes that
incoherence but changing the form to let field info_session_confirmed
not required.

beesdoo_easy_my_coop/views/subscription_templates.xml

@@ -14,7 +14,6 @@
                   <input type="checkbox"
                     class="form-control"
                     name="info_session_confirmed"
-                    required="True"
                     t-attf-value="#{info_session_confirmed or ''}"/>
               </div>
               <div class="col-md-6 col-sm-6">